The blue whale is an ocean-dwelling mammal that is the largest animal to have ever lived on the planet. It can grow up to 110 feet in length and may weigh up to 300,000 lbs. It feeds on plankton and krill, which are sieved through filters in its mouth that take the place of teeth. The blue whale is found throughout the world's oceans.
Blue whales are found in cold or temperate waters and prefer deeper ocean waters to coastal waters. They occur in all the major oceans of the world. Their habitats include the Southern Caribbean Sea, the Sea of Cortez Global 200 Ecoregions and the Icelandic and Celtic Marine Ecosystems. According to the website Blue-Whale.info, there are approximately 2,000 blue whales living off the Californian coast.
The blue whale's populations have been severely depleted due to commercial whaling, which was eventually banned in 1964. They still appear to be in very low numbers around the Antarctic and they still haven't returned to the seas around Japan. Animal Info also reports that they are also scarce around the Gulf of Alaska and the Bering Sea, where they were once a common sight.
Increase in Numbers
Since the introduction of the ban on commercial whaling, it is believed that the overall numbers of blue whales have increased and they are now appearing in seas they had once frequented. They were spotted off the west coast of Norway in 1988. This was the first time they had been seen there for 30 years.
Blue whales in both the northern and southern hemisphere head to the poles during the summer months to feed. This is followed in the winter by a migration back to warmer equatorial regions, where they breed.
A blue whale can dive as far as 330 feet in order to feed. These dives can last anywhere from 10 to 20 minutes. When it resurfaces, the whale forces out what is known as a "blow," which is a combination of air from its lungs, ocean water and mucus.